Google Plus Pushes Invalid HTML (2012)

By Xah Lee. Date: . Last updated: .

Google Pushes Invalid HTML to the World, this: 

<g:plusone annotation="inline"></g:plusone>

So, Google started a Google Plus social network. Along with it is a Google Plus button, it looks like this:

social network share buttons
Social Network Share Buttons

To add Google Plus button, you get the code at the official Google site at http://www.google.com/webmasters/+1/button/ .

google pushes invalid html 2014-09-19
Google tells webmasters to add invalid HTML on their page.

Invalid HTML!

isn't Google supposed to be this ethical company who promotes good coding practices and HTML5 for a better world?

addendum: This page used to also claim Twitter and Facebook using HTML: Custom Data Attribute as invalid. That is incorrect. Thanks to ArgV for correction.